First off, Charles, thanks for your reply.
After your advice I started googling xorg cof files configs for my viewsonic.
after hunting a little while, I found out how to have the computer auto detect from command line using putty on my other comp.
After reboot the viewsonic monitor is showing my GUI!
For those of you with the same problem using a debian or Ubuntu, this is
what I did:
using putty.exe from another computer on your network,
(You have to be root user)
It will walk you through graphics set up and auto detect your monitor.
Hope that helps anyone else in the same situation.